SectionB

　　Directions：In the following article, some sentences have been removed. For questions41-45, choose the most suitable one from the list A~G to fit into each of the numbered blank. There are two extra choices, which do not fit in any of the gaps.(10points)

　　Researchers have found that drugs used to treat human seizures can delay aging in worms by as much as 50 percent. The roundworms used for the study are similar to humans in their molecular makeup, raising the

　　possibility that the drugs could also extend the life span of humans.

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　　“By finding a class of drugs that delays aging we have found a relationship between the function of the nervous system and aging that was not well understood, ” said Kerry Komfeld, a geneticist at the Washington

　　University School of Medicine in St. Louis, Missouri. The findings are detailed this week in the journal Science.

　　The discovery came out of the thesis work by one of Komfeld’s graduate students, Kimberley Evason. About four years ago, Evason began exposing groups of the roundworm Caenorhabditis elegans to commercially available drugs to see if the drugs would delay aging or promote longevity.

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　　Over eight months the scientists tested 20 drugs, all with negative results. Finally they tested the anticonvulsant drug ethosuzimide. Researchers found that the drug extended the life span of roundworms from 16. 7 days to 19. 6 days, a 17 percent increase.

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　　The discovery that the drugs extend the life span of roundworms could have important implications fox human aging as well. There are strong similarities on the molecular level between the proteins and genes that

　　constitute the worm and those that make up other animals, including humans.

　　“Many basic processes are highly related, including neural function, insulin signaling, and probably important aspects of the aging process, ” Komfeld said. “There’s every reason to think that these animals an a good model for higher animals, such as people. ”